Biomedical subjects
M C Soulen
Publications and source records attributed to M C Soulen.
Enlargement of the pancreatic head in patients with pancreas divisum.
Pancreas divisum (PD) is a congenital anomaly present in 6-10% of the population. Computed tomography (CT) examinations in eight of 15 patients (53%) with endoscopic retrograde pancreatography (ERCP)-proven PD were interpreted as showing enlargement of the pancreatic head. Two of these had carcinoma, three had pancreatitis limited to the ventral pancreas, and three were normal. Criteria to distinguish nonpathologic enlargement of the pancreatic head due to PD alone from pathologic causes may include homogeneous parenchyma and an absence of other abnormal signs on CT. Because PD may simulate a pancreatic head mass, the radiologist should be familiar with this variant, and ERCP should precede biopsy unless other evidence of malignancy is present.
Bacterial renal infection: role of CT.
The imaging studies done on 62 patients hospitalized for acute renal infections were retrospectively reviewed. Thirty-six (58%) had one or more abscesses, 17 (27%) had focal or diffuse acute bacterial nephritis, five (8%) had pyonephrosis, and four (6%) had pyelonephritis. All had prolonged fever (greater than or equal to 72 hours) and leukocytosis. Among 25 patients examined with both ultrasound (US) and computed tomography (CT), US failed to depict three of five (60%) cases of acute bacterial nephritis and seven of 15 (47%) intrarenal and extrarenal abscesses. One renal abscess was misdiagnosed as a tumor at CT. US is not an adequate screening test for detecting lesions that may require invasive therapy. CT is more sensitive for the detection of acute renal inflammatory disease and for defining the extent of disease for planning of radiologic or surgical intervention.
Sequelae of acute renal infections: CT evaluation.
Seventeen patients with upper urinary tract infection who underwent 51 computed tomographic studies (two to five per patient; mean, three) were retrospectively evaluated. Five to 10 days after the initial examination, there was little change in parenchymal abnormalities, but perirenal inflammation worsened and then subsided over 2-8 weeks. Enlargement of the affected kidney, present initially in 12 patients, persisted up to 6 weeks and resolved by 10-16 weeks. Abnormalities of parenchymal contrast material enhancement persisted for 1-2 months. New cortical scars appeared in six of 12 patients with an initially normal renal contour and in one of five patients who had scars initially. Three patients with a renal abscess developed a new calyceal diverticulum, presumably by rupture of the abscess into the collecting system. The present study shows that abnormalities of renal size and enhancement persist for weeks to months after clinical signs of infection resolve and that scarring in adults with urinary tract infection occurs more frequently than was previously realized.
Cryptosporidiosis of the gastric antrum: detection using CT.
We describe a patient who had cryptosporidiosis and cytomegalovirus infection of the gastric antrum that was initially detected on computed tomography (CT) scans. CT may be useful in the evaluation of immunocompromised patients with diarrheal illness, as well as in the assessment of the gastrointestinal tract.
Subclavian artery angioplasty proximal to a left internal mammary-coronary artery bypass graft: case report.
Subclavian artery angioplasty is an established treatment for subclavian steal syndrome and arm ischemia caused by subclavian stenosis. We report a case of angina pectoris caused by a subclavian artery stenosis proximal to a left internal mammary-coronary artery bypass graft. Angioplasty was performed without complication and with complete relief of symptoms. Reactive hyperemia was induced in the forearm and hand with a blood pressure cuff prior to angioplasty to increase blood flow to the arm, and to reduce the chance of graft embolization. Repeat angiography 6 months later confirmed continued patency of the subclavian artery and the graft and reversal of the steal physiology. The patient remains symptom free 15 months after angioplasty.
Use of articulated catheters in the treatment of biliary strictures.
We have used a single articulated catheter to obviate the need for multiple catheters in patients with complex biliary strictures or strictures associated with small or immature tracts. Two- and three-arm articulated drains (8-14 Fr) made from segments of biliary catheters were placed in 16 patients. Nine were placed transhepatically, 6 transperitoneally through existing T-tube tracts, and 1 through a cystic duct fistula. Six malignant and 10 benign strictures were stented with various catheter configurations through a single tract. Fifteen patients had two catheter components with one articulation and 1 patient had three catheter components with two articulations. The average duration of catheter drainage was 7.0 +/- 4.2 months. Routine catheter exchanges were performed; two spontaneous occlusions occurred. In patients where internal stenting may be difficult or undesirable, articulated catheters allow satisfactory external and internal drainage of complex benign and malignant strictures through a single tract, avoiding the need for multiple transhepatic catheters.
Elective embolization for prevention of hemorrhage from renal angiomyolipomas.
PURPOSE: Among angiomyolipomas 4 cm or larger, 82%-94% are symptomatic and 50%-60% bleed spontaneously. Up to one-third of patients with these lesions present in shock. The effectiveness of elective embolization was evaluated in the prevention of bleeding from large (> or = 4 cm) angiomyolipomas while sparing the normal renal parenchyma. PATIENTS AND METHODS: Five cases from the authors' institution and 21 cases from the literature were reviewed retrospectively. RESULTS: Embolization as the sole means of treatment was effective in 90% of patients over a follow-up period from 2 months to 7 years (mean, 21 months). There were no complications at the authors' institution. Serious procedure-related complications reported in the literature were limited to two cases of aneurysm rupture and two necrotic tumors requiring percutaneous drainage. CONCLUSION: Embolization of renal angiomyolipomas is safe and well tolerated and may be of benefit in preventing life-threatening hemorrhage.
Chemical ablation of the gallbladder: evaluation of multiple agents in vitro.
PURPOSE: To find a more effective chemical regimen for transcatheter ablation of the gallbladder in an in vitro model. MATERIALS AND METHODS: Sectioned and whole pig gallbladders were exposed in vitro to 12 different chemical solutions at varying conditions of exposure time, pH, and temperature. RESULTS: In the in vitro studies, 0.1 N and 1.0 N solutions of sodium hydroxide in water or ethanol and 3% hydrogen peroxide were the most effective sclerosant agents. Ethanol and hydrochloric acid failed to completely eliminate the epithelium from the gallbladder sections. Increasing exposure time from 10 to 20 minutes or increasing the temperature of the solutions from 37 degrees C to 50 degrees C did not alter these results. Sequential 15-minute exposures to 0.1 N sodium hydroxide in ethanol followed by peroxide completely eliminated the epithelium from whole gallbladders in vitro. CONCLUSION: Alkaline solutions and hydrogen peroxide are more effective than ethanol alone, acids, or detergents in eliminating gallbladder epithelium in this model. Further evaluation of these agents in vivo is merited.
Percutaneous management of external pancreatic fistulas: the use of articulated and metal stents.
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Phlegmasia cerulea dolens of the upper extremity.
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Chemical ablation of the gallbladder: is it feasible?
PURPOSE: Transcatheter ablation of the gallbladder has been attempted in animals and humans with a variety of chemical and physical agents. Initial in vitro experiments suggested sodium hydroxide and hydrogen peroxide were more effective sclerosants than previously reported chemical agents. A phase I trial of escalating concentrations of and exposure times to these agents was performed in vivo. MATERIALS AND METHODS: Fourteen domestic pigs underwent cholecystostomy tube placement and cystic duct ligation. Two weeks later, sclerosis was performed with sodium hydroxide/ethanol solutions and hydrogen peroxide. RESULTS: Sequential 15- or 30-minute exposures to 0.1 N solutions of sodium hydroxide in ethanol followed by 3% peroxide failed to completely eliminate the pig gallbladder epithelium in vivo; 0.5 N and 1.0 N sodium hydroxide in ethanol caused gross gallbladder hemorrhage, mural dissection, and one perforation. Although the gallbladder lumen was ablated, the gallbladder epithelium was not completely eliminated in any animal. CONCLUSION: Chemical ablation of the pig gallbladder epithelium was not feasible in this experimental model.
Transjugular intrahepatic portosystemic shunt-related arterial injuries: prospective comparison of large- and small-gauge needle systems.
PURPOSE: The authors prospectively compared the nature and incidence of hepatic arterial injuries resulting from creation of a transjugular intrahepatic portosystemic shunt (TIPS) with large- and small-gauge needle systems. PATIENTS AND METHODS: Fifty patients underwent hepatic and superior mesenteric angiography immediately before and after shunt creation. A sheathed 16-gauge needle system was used to locate and puncture the portal vein in 24 patients. A 21-gauge needle system was used in 26 patients. RESULTS: Shunts were successfully created in all patients. Three inadvertent hepatic arterial punctures were recognized during shunt placement, two with the small needle and one with the large needle system. No hepatic arterial lesions were detected in any patient. Two incidental hepatomas were identified at angiography. CONCLUSION: TIPS-related hepatic arterial injuries are rare. In this series, large and small needle systems were indistinguishable with respect to this complication.
Transvenous removal of fibrin sheaths from tunneled hemodialysis catheters.
PURPOSE: Long-term hemodialysis catheters are prone to significant dysfunction due to fibrin accumulation around their tips. The authors assessed the efficacy of transvenous snare removal of fibrin to prolong function of these catheters. PATIENTS AND METHODS: Twenty-four procedures were performed in 20 patients with tunneled hemodialysis central venous catheters. Technical success was gauged by venography and the ability to infuse and aspirate catheters. Durable efficacy was assessed by improvement in hemodialysis. RESULTS: Twenty-two of 24 procedures were performed successfully. In two cases residual material remained despite repeated stripping. Mean preprocedure hemodialysis blood-liters processed per hour increased from 15.1 to 19.1 L/h in the first dialysis session after stripping, and blood flow rates of 300 mL/min or greater were restored. By the fifth dialysis session after stripping, the blood-liters processed per hour dropped to 15.9 L/h as catheter flow rates returned to unacceptable levels. CONCLUSIONS: Percutaneous fibrin removal with a loop snare provides no durable benefit in improving function of failing hemodialysis catheters.
Mechanical declotting of thrombosed dialysis grafts: experience in 86 cases.
PURPOSE: To evaluate the efficacy, safety, and primary patency of percutaneous mechanical declotting of thrombosed dialysis grafts using latex balloons. MATERIALS AND METHODS: Fifty-nine patients with 86 episodes of dialysis graft thrombosis underwent percutaneous mechanical declotting with balloons using crossing catheter or transjugular technique. Vital signs, peripheral oxygenation, technical success, procedure time, and complications were recorded prospectively. Technical success was defined as a patent graft at the completion of the procedure. Clinical success, defined as successful dialysis for 1 week, and primary patency were obtained retrospectively from review of the dialysis records. RESULTS: Technical success was achieved in 74 of 86 procedures (86%). Median procedure time was 115 minutes, including failed cases. Ten of the 12 technical failures were due to resistant vascular stenoses precluding graft patency, despite removal of thrombus. There were no immediate complications. One patient died of sepsis 4 days after declotting. Clinical success was achieved after 65 of 86 procedures (76%); nine grafts thrombosed within 1 week of a technically successful declotting procedure. Primary patency (including technical failures) was 37% at 3 months, 31% at 6 months, and 17% at 12 months. CONCLUSION: Mechanical declotting is an effective means of restoring patency to thrombosed dialysis grafts.
Percutaneous varicocele embolization versus surgical ligation for the treatment of infertility: changes in seminal parameters and pregnancy outcomes.
PURPOSE: To compare the success of percutaneous varicocele embolization to surgical ligation with regard to changes in semen characteristics and pregnancy outcome. MATERIALS AND METHODS: Infertility records from 346 men who underwent correction of their varicocele for infertility (surgical ligation 149; embolization 197) were reviewed retrospectively. Preprocedural and postprocedural semen analyses and pregnancy outcomes were obtained with use of chart and telephone follow-up. RESULTS: In men who successfully impregnated their partners, there were significant improvements in sperm density, percent total improvement, motility, and progression. Postprocedural (embolization vs surgery) percentage increases in seminal parameters were density, 156.8% versus 138.5%; total, 168.8% versus 157.91%; and motility, 2.7% versus 3.2%. The percent of individuals who had a change in sperm progression was 31% versus 41%. There was no statistical difference between the techniques based on t tests. The pregnancy rates were similar for the two groups, 39% and 34% for embolization and surgery, respectively. CONCLUSION: There is no significant statistical difference in seminal values or pregnancy outcome between the two techniques.
Bilateral adrenal hemorrhage resulting in acute adrenal insufficiency as an unusual complication of hepatic arterial chemoembolization.
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Replacement of failing tunneled hemodialysis catheters through pre-existing subcutaneous tunnels: a comparison of catheter function and infection rates for de novo placements and over-the-wire exchanges.
PURPOSE: Tunneled hemodialysis catheter dysfunction often occurs from fibrin sheath formation. As a way to preserve existing catheter venous access sites, the authors evaluated over-the-wire exchange of catheters through pre-existing subcutaneous tunnels as an alternative to catheter removal and de novo catheter replacement. PATIENTS AND METHODS: One hundred nineteen catheters were placed in 68 patients. Seventy-seven catheters were placed de novo and 42 catheters were placed through the pre-existing subcutaneous tunnels of failing catheters. Technical success, short-term complications, infection rates, and functional catheter longevity were evaluated. RESULTS: Technical success for catheter exchange was 93%. Infection rates were comparable to those of de novo catheter placement: 0.15 and 0.11 infections per 100 catheter days for de novo and exchanged catheters, respectively. Catheter duration of function was not significantly different for de novo versus exchanged catheters: 63% and 51% at 3 months, 51% and 37% at 6 months, and 35% and 30% at 12 months, respectively. CONCLUSIONS: Over-the-wire exchange of tunneled hemodialysis catheters is safe and easily performed. It causes no increase in infectious complications and provides similar catheter longevity to de novo catheter placement. The procedure is an important option for prolonging tunneled hemodialysis catheter access sites.